Basics and Some Theory of AnTherm
Graphic Representation of Heat Flow
Since the heat flow pattern of a thermal bridge is characteristically more
complex than the single-direction flow through a planar component, graphic
illustrations of bridge flow patterns can provide critical information at a
glance.
heat flow diagram |
One method of visualising two dimensional heat flow is to
delineate the
direction of flow (vector) through the building component with lines drawn
at prescribed intervals. The area bounded by two lines in the diagram
represents a heat quantity defined by the interval (e.g. given 10 intervals,
the heat flow between two lines corresponds to 10% of the total heat flow in
one direction through the surface of a given space). The denser the lines in
a region of such a diagram, the more heat flows through this region. Thus
local peaks of heat loss (and predictably cold surface points) are easily
discernible.
Due to the two-dimensionality of graphic illustrations, however,
three-dimensional heat flow patterns cannot be meaningfully rendered with
such a diagram. Therefore the three-dimensional rendering provides one
streamline through the
arbitrarily chosen point.
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isotherms |
The second common method of heat flow representation is to
render the temperature distribution in a component with isotherms, i.e. by
delineating lines of the same temperature at defined intervals. Isotherms
lie normal to the direction of heat flow, thus providing an "inverted"
rendering of the heat flow pattern (denser isotherms correspond to regions
of increased heat flow).
Since isotherms represent a two-dimensional section through a temperature
distribution rather than vectors directly, the isotherm method is also
suited for (partial) rendering of three-dimensional heat flow situations (on
surfaces or slices).
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heat flux diagram |
Further method of heat flow representation is to render the
heat flux distribution in a component - e.g. as
colorized representation of values on on
surfaces or slices or
with isolines of the same heat flow density. Such rendering provides clear
heat flow pattern and allows easy identification of regions of increased heat flow.
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isosurface |
For the three dimensional case the use of isosurface
provides valuable alternative to isolines.
As for isolines the isosurface is useful to emphasize a surface of same temperature and to assess the irregularities of
temperature distribution within the components body in 3D.
The isosurface of the temperature field lies normal to the direction of heat flow, thus providing an "inverted" rendering of
the heat flow pattern.
By utilizing the view onto the isosurface of equal values of
heat flux one can visualize areas of increased heat flow rates and by that easily identify design, geometrical or
material weak spots of the building component in three dimensional renderings.
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